Fine substrate sediments are considered to be important in the management of urban river systems. Urban construction activities have been reported to increase sediment loads causing the temporary siltation of channel substrates within the urban area. Nevertheless fine sediment derived from urban areas frequently carry toxic material well in excess of background concentration levels. While the soluble phase of heavy metals and the importance of their association with suspended sediment has received considerable attention, longer term studies of fine urban river-bed sediments are limited. Furthermore studies of heavy pollutants in active stream sediments, below mine waste tips, have shown the channel substrate can provide a long term store for heavy metals in association with fine sediments. This thesis investigates the variety of impacts that urbanisation has upon the sedimentation of gravel bed rivers. A freeze coring technique and infIltration baskets have been used to study the textural-geochemical properties of fme matrix sediment and its development within an urban river-bed framework, within and below a number of contrasting urban catchments in the U.K. Complex urban hydrological and sedimentological regimes are shown to have a variable influence upon matrix sedimentation. The actual volume of matrix present within the urbanised substrate is influenced by the degree of urbanisation within the catchment. Furthermore this sediment is finer in size and associated heavy metal concentrations are well in excess of natural background levels. Although heavy metal levels do correlate slightly with textural characteristics, the presence of maximum concentrations at depth in the substrate indicate possible mobilisation of metals within the urbanised river-bed. The temporal behaviour of matrix development within an urbanised substrate is shown to differ from natural river-beds. Despite high suspended sediment concentrations the magnitude of the potential rate of supply is lower, by 50 percent, and dominated by organic material. This sediment also contains elevated heavy metal cocnentrations. This contrasts to the inorganic sediment ingress of natural river substrates. It is concluded that fine matrix sediments within urban gravel bed rivers should be at least of concern to public health engineers, water authorities and conservationists.

A thesis submitted for the degree of Doctor of Philosophy in the Faculty of Science at the University of the Witwatersrand. / The present thesis is divided into three parts. The study described in Part I arose out of a request by the Chamber of Mines Mining Research Laboratory to the National Institute for Metallurgy to undertake a preliminary study of whether it would be feasible, in Witwatersrand conglomerates, to carry out rapid delimitation of areas rich in gold and/or uranium at the rock face, a procedure which would permit areas of rich ore to be removed selectively by means of the "rock-cutter". The approach adopted in this study was essentially geochemical, while conventional mineralogical techniques (macro-auto radiographs , thin section and polished section analyses) provided a control. The samples were drawn from the Vaal Reef at Hartebeestfontein and Zandpan and from the Ventersdorp Contact Reef at Venterspost, and were analysed quantitatively for gold, silver, uranium, pyrite, muscovite, pyrophyllite, chlorite, quartz, iron, potassium, nickel, titanium, zirconium and chromium. The intensity of the interrelationships between the elements and minerals analysed for was examined statistically by means of correlation covariance and factor analysis programmes written for an IBM 360/50 digital computer. A sympathetic relationship -- defined as significant positive correlation (with a correlation coefficient r> 0. 7) -- was found to exist between gold and uranium in both the Vaal Reef and Ventersdorp Contact Reef samples. These findings suggest that gold and uranium can be removed Simultaneously by means of the rock-cutter, and that radioactivity can be used as an indicator for on-site delimitation of areas rich in gold. In the course of the study described in Part I, it became evident that little detailed mineralogical work had ever been done on the phyllosilicates occurring in the Witwatersrand System. Accordingly, certain phyllosilicates from Witwatersrand conglomerate bands and other sources were examined in detail, this study being described in Part II of the present thesis. This study called for detailed chemical, optical, X-ray crystallographic, infra-red, differential thermal and thermogravimetric analyses, the results of which are presented. The findings were examined in the light of variolls classification schemes that have bep proposed for the phyllosilicates. This investigation revealed the need for a universally acceptable system of classification for the phyllosilicates, which should preferably be drawn up under the auspices of the International Mineralogical Association to avoid the confusion that exists at present. Part III of the present thesis is devoted to a discussion and description of various analytical techniques that had to be modified or developed to meet th8 requirements of the studies described in Parts I and II. The techniques described include: (1) An X-ray diffraction method which was developed for the quantitative analysis of pyrite, muscovite, pyrophyllite, chlorite and quartz in crushed ore from Witwatersrand conglomerates. This method makes use of novacul iie as an external standard and of binary mixtures as analytical standards, and had a mean absolute error of 1. 1 %. This method may be expanded to permit analysis of an n-component mixture. (2) A whole rock pressed powder technique of X-ray fluorescence analysis which was used for the quantitative determination of iron, potassium, nickel, titanium, zirconium and chromium. This method makes use of internstional rock standards as external standards. Six computer programmes used for the computation of the analytical results and in the statistical and crystallographic calculations are also presented in Part III. / AC2017

Observa-se atualmente uma evolução significativa do conhecimento nas áreas relacionadas às geociências. E, em particular a ciência geomorfológica, a qual tem como premissa compreender e explicar as formas da arquitetura do relevo na atualidade através de sua gênese, evolução cronológica e grau de estabilização partindo de estudos descritivos e investigativos. Tais avanços estão respaldados em novas geotecnologias e consequentemente na aplicação de metodologias específicas que permitem uma vasta possibilidade de novas pressuposições indicativas ou elucidativas sobre o sistema geomorfológico. Desta forma este trabalho tem como objetivo averiguar qual a possível influência dos aspectos geoquímicos sobre o estado atual das unidades de relevo associados aos fatores e elementos geoambientais, em litologias diferenciadas através da aplicação de procedimentos metodológicos envolvendo a utilização de geotecnologicas e investigações geoquímicas. Para a realização e êxito desta proposta metodológica definiu-se coma área de estudo a bacia hidrográfica do rio Pequeno em seu terço médio e superior, situada no município de São José dos Pinhais, integrante da Região Metropolitana de Curitiba no Estado do Paraná região sul do Brasil. Optouse por este recorte espacial em função do mesmo apresentar as características geoambientais apropriadas para o desenvolvimento deste trabalho. Os procedimentos metodológicos adotados consistem na utilização da análise de produtos elaborados a partir das técnicas do sensoriamento remoto e geoprocessamento para a confecção da cartografia temática. Produtos estes associados à investigação geoquímica do material de alteração (saprólito) em rochas do embasamento cristalino tomando como objeto de estudo vertentes contra postas uma em relação a outra em duas áreas amostrais distintas. Para a investigação geoquímica optou-se pelo método da varredura semi-quantitativa dos óxidos através da espectrometria de fluorescência de raios “X" em amostras de materiais intermediários entre os estudos geoquímicos orientativos do solo e litogeoquímicos orientativos. Considera-se que para os ensaios metodológicos a que se propõe este trabalho os resultados foram satisfatórios com a ressalva para a importância de estudos mais detalhados, envolvendo mais análises propiciando assim maior confiabilidade nas correlações geoquímicas com a interpretação e compreensão das formas do relevo atual. Entretanto ressalta-se a importância destes resultados não como respostas elucidativas e sim como mais uma possibilidade metodológica investigativa viável para a compreensão do sistema geomorfológico quanto sua gênese, evolução e grau de estabilidade. / A significant evolution of knowledge on geosciences and its related topics can be observed nowadays. It happens, in particular, with the geomorphologic science, which has, as its premise, to understand and to explain the current relief architecture form based on its genesis, chronological evolution and stabilization degree having, as starting point, descriptive and investigative studies. Such developments are supported by new geotechnologies and, consequently, by the application of specific methodologies that allow a broad possibility of new indicative or elucidative propositions about the geomorphologic system. Therefore, the objective of this work is to verify the possible influence of geochemical aspects on the current relief units’ state related to geoenvironmental elements, in different lithologies through the application of methodological procedures involving the application of geotechnologies and geochemical research. In order to successfully accomplish this methodological proposal the higher third mean of the “Pequeno" river watershed was defined as the area of study. This area is located in São José dos Pinhais municipality in the Curitiba metropolitan area, in Paraná state, in south region of Brazil. Such special cut was adopted because of the suitability of its geoenvironmental characteristics to the right and proper execution of this work. The adopted methodological procedures consist in the use of the analysis of products prepared based on remote sensing techniques and geoprocessing in order to produce the thematic cartography. Such products are associated to the geochemical research of the alteration material (saprólito) in the crystalline basement rocks, having as object of interest opposed strands in two distinct sample areas. When concerning the geochemical study, the oxide semi-quantitative scan method using x-ray fluorescent spectrometry was adopted. It was performed in intermediate material samples between the geochemical orientated and lithogeochemical orientated soil studies. Considering the methodological essays proposed in this work, the obtained results are satisfactory. It is important, however, to perform more detailed studies with more analysis with the purpose of having more confidence regarding the geochemical relations with the interpretation and understanding of the current relief forms. Nevertheless, it is important to stress the importance of these results, not as clarifying answers, but as another feasible possibility to understand the geomorphologic system regarding its genesis, evolution and stability degree.

Observa-se atualmente uma evolução significativa do conhecimento nas áreas relacionadas às geociências. E, em particular a ciência geomorfológica, a qual tem como premissa compreender e explicar as formas da arquitetura do relevo na atualidade através de sua gênese, evolução cronológica e grau de estabilização partindo de estudos descritivos e investigativos. Tais avanços estão respaldados em novas geotecnologias e consequentemente na aplicação de metodologias específicas que permitem uma vasta possibilidade de novas pressuposições indicativas ou elucidativas sobre o sistema geomorfológico. Desta forma este trabalho tem como objetivo averiguar qual a possível influência dos aspectos geoquímicos sobre o estado atual das unidades de relevo associados aos fatores e elementos geoambientais, em litologias diferenciadas através da aplicação de procedimentos metodológicos envolvendo a utilização de geotecnologicas e investigações geoquímicas. Para a realização e êxito desta proposta metodológica definiu-se coma área de estudo a bacia hidrográfica do rio Pequeno em seu terço médio e superior, situada no município de São José dos Pinhais, integrante da Região Metropolitana de Curitiba no Estado do Paraná região sul do Brasil. Optouse por este recorte espacial em função do mesmo apresentar as características geoambientais apropriadas para o desenvolvimento deste trabalho. Os procedimentos metodológicos adotados consistem na utilização da análise de produtos elaborados a partir das técnicas do sensoriamento remoto e geoprocessamento para a confecção da cartografia temática. Produtos estes associados à investigação geoquímica do material de alteração (saprólito) em rochas do embasamento cristalino tomando como objeto de estudo vertentes contra postas uma em relação a outra em duas áreas amostrais distintas. Para a investigação geoquímica optou-se pelo método da varredura semi-quantitativa dos óxidos através da espectrometria de fluorescência de raios “X” em amostras de materiais intermediários entre os estudos geoquímicos orientativos do solo e litogeoquímicos orientativos. Considera-se que para os ensaios metodológicos a que se propõe este trabalho os resultados foram satisfatórios com a ressalva para a importância de estudos mais detalhados, envolvendo mais análises propiciando assim maior confiabilidade nas correlações geoquímicas com a interpretação e compreensão das formas do relevo atual. Entretanto ressalta-se a importância destes resultados não como respostas elucidativas e sim como mais uma possibilidade metodológica investigativa viável para a compreensão do sistema geomorfológico quanto sua gênese, evolução e grau de estabilidade. / A significant evolution of knowledge on geosciences and its related topics can be observed nowadays. It happens, in particular, with the geomorphologic science, which has, as its premise, to understand and to explain the current relief architecture form based on its genesis, chronological evolution and stabilization degree having, as starting point, descriptive and investigative studies. Such developments are supported by new geotechnologies and, consequently, by the application of specific methodologies that allow a broad possibility of new indicative or elucidative propositions about the geomorphologic system. Therefore, the objective of this work is to verify the possible influence of geochemical aspects on the current relief units’ state related to geoenvironmental elements, in different lithologies through the application of methodological procedures involving the application of geotechnologies and geochemical research. In order to successfully accomplish this methodological proposal the higher third mean of the “Pequeno” river watershed was defined as the area of study. This area is located in São José dos Pinhais municipality in the Curitiba metropolitan area, in Paraná state, in south region of Brazil. Such special cut was adopted because of the suitability of its geoenvironmental characteristics to the right and proper execution of this work. The adopted methodological procedures consist in the use of the analysis of products prepared based on remote sensing techniques and geoprocessing in order to produce the thematic cartography. Such products are associated to the geochemical research of the alteration material (saprólito) in the crystalline basement rocks, having as object of interest opposed strands in two distinct sample areas. When concerning the geochemical study, the oxide semi-quantitative scan method using x-ray fluorescent spectrometry was adopted. It was performed in intermediate material samples between the geochemical orientated and lithogeochemical orientated soil studies. Considering the methodological essays proposed in this work, the obtained results are satisfactory. It is important, however, to perform more detailed studies with more analysis with the purpose of having more confidence regarding the geochemical relations with the interpretation and understanding of the current relief forms. Nevertheless, it is important to stress the importance of these results, not as clarifying answers, but as another feasible possibility to understand the geomorphologic system regarding its genesis, evolution and stability degree.